It’s the ones in the middle who sway one way or another. Trump is being ungracious by continuing to post about how horrible Biden has been (in his opinion). Its very un-presidential on Trump's part, and shows the real lack of class that he is well known for. This is the kind of thing that pushes people in the middle one way or the other. It also demonstrates that he has trouble keeping his mouth shut even when he know that running his mouth is going to hurt him.